intro to clinical trials: a very brief introduction

Clinical trials are structured research studies to determine whether a medical treatment, device, or strategy is safe and appropriate for humans. Trials determine what works for specific conditions or may be superior to existing approaches. Before well-designed clinical testing was developed, medical solutions were hit-or-miss, and people often received treatments that hurt more than helped.

Clinical trials are intended to determine the safety, effectiveness, and potential side effects of certain procedures or medicines. Since “doing no harm” is the central principle of bioethics, clinical trials must first ensure complete safety.

Phases of a Clinical Trial

The Federal Drug Administration (FDA) requires that clinical trials pass four phases to achieve acceptance for general use. These are sequential, and products must obtain FDA approval to move to the next phase.

Phase 1: The first phase consists of a small sampling of study participants and patient recruitment, either healthy patients or ones with the target disease. Phase 1 is designed to test the safety and dosage of the product and may involve 100 or so participants over several months. According to the FDA, about 70 percent pass to Phase 2.

Phase 2: This phase involves testing with several hundred people who have the targeted condition to determine the product’s efficacy and potential side effects. The FDA reports that 33 percent pass on to Phase 3.

Phase 3: While lasting from one to four years, the third phase monitors the overall treatment benefit to the defined population. More safety information is gathered. An average of 25 percent of trialed products succeed and are approved for broader market testing by the FDA.

Phase 4: A program of Ongoing Post Market Safety Monitoring continues as the FDA monitors longer term product safety.

Blind or Double Blind

Clinical trials must be unbiased. To assure the results are accurate, clinical participants frequently are unaware of which product they may be sampling. Sometimes the comparison may be a comparison between a “standard” medication against the trial product to determine their relative effects. At other times, a harmless placebo may be used. These trials are considered "blind."

Sometimes even the doctors and technicians administering the tests are unaware of which products they are giving to their trial participants. When neither the participants nor the administrators are aware, the trial is designated as “double blind.”

Double blind testing eliminates any possibility for overzealous doctors or technicians to skew a clinical trial in any way.